Physocarpus plant named &#39;SMNPOTWG&#39;

ABSTRACT

A new and distinct  Physocarpus  cultivar named ‘SMNPOTWG’ is disclosed, characterized by a small plant form, early flowering, smaller leaves, mildew resistance and abundant red-purple colored flowers. The new variety is a  Physocarpus , normally produced as an outdoor garden or container plant.

Latin name of the genus and species: Physocarpus opulifolius.

Variety denomination: ‘SMNPOTWG’.

BACKGROUND OF THE INVENTION

The new Physocarpus cultivar is a product of a planned breeding programconducted by the inventor, Timothy D. Wood, in Grand Haven, Minn. Theobjective of the breeding program was to produce new Physocarpusvarieties with unique foliage and powdery mildew resistance. The openpollenation resulting in this new variety was made during Summer of2010.

The new Physocarpus ‘SMNPOTWG’ resulted from an open pollination inwhich seed was collected from an unnamed, unpatented proprietaryseedling. Various Physocarpus were present in the field, making accurateidentification of the pollen parent impossible. The new variety wasidentified as a potentially interesting selection in the Summer of 2013,at a commercial nursery in Grand Haven, Minn.

Asexual reproduction of the new cultivar ‘SMNPOTWG’ by softwood cuttingswas first performed during the Summer of 2013, at commercial greenhousein Grand Haven, Minn. Subsequent propagation has shown that the uniquefeatures of this cultivar are stable and reproduced true to type in 3successive generations.

SUMMARY OF THE INVENTION

The cultivar ‘SMNPOTWG’ has not been observed under all possibleenvironmental conditions. The phenotype may vary somewhat withvariations in environment such as temperature, day length, and lightintensity, without, however, any variance in genotype.

The following traits have been repeatedly observed and are determined tobe the unique characteristics of ‘SMNPOTWG’ These characteristics incombination distinguish ‘SMNPOTWG’ as a new and distinct Physocarpuscultivar:

-   -   1. Smaller plant size.    -   2. Smaller leaves.    -   3. Yellow-Green leaves.    -   4. Good mildew resistance.    -   5. Flowering at a younger age.    -   6. Good performance in containers.

PARENT COMPARISON

Plants of the new cultivar ‘SMNPOTWG’ are similar to plants of theparent, in most horticultural characteristics, however, plants of thenew cultivar ‘SMNPOTWG’ differ in the following:

-   -   1. Improved resistance to mildew.    -   2. Flowers at a younger age than the parent variety.    -   3. ‘SMNPOTWG’ is a dwarf, the parent is full sized.    -   4. The new variety has Yellow-Green foliage, the parent has        yellow foliage with red new growth.

COMMERCIAL COMPARISON

Plants of the new cultivar ‘SMNPOTWG’ can also be compared to thecommercial variety Physocarpus opulifolius ‘Bert Dart's Gold’,unpatented. The varieties are similar in most horticulturalcharacteristics; however ‘SMNPOTWG’ differs in the following:

-   -   1. The new variety is a dwarf plant, this comparator is a        semi-dwarf.    -   2. The new variety has smaller leaves than this comparator.    -   3. The new variety blooms more consistently and abundantly at a        younger age than this comparator.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying photograph in FIG. 1 illustrates in full color atypical 2 year old plant of ‘SMNPOTWG’ grown in a 2 gallon container.

FIG. 2 illustrates in full color a typical inflorescence and foliage of‘SMNPOTWG’ grown outdoors in Grand Haven, Minn., in a garden setting.The photographs were taken using conventional techniques and althoughcolors may appear different from actual colors due to light reflectanceit is as accurate as possible by conventional photographic techniques.

DETAILED BOTANICAL DESCRIPTION

In the following description, color references are made to The RoyalHorticultural Society Colour Chart 1996 except where general terms ofordinary dictionary significance are used. The following observationsand measurements describe ‘SMNPOTWG’ plants grown outdoors in GrandHaven, Minn. This occurred during June of 2014. The plants wereapproximately 2 years old grown in 2 gallon containers. The growingtemperature ranged from 18° C. to 27° C. during the day, and 5° to 10°C. at night. The field is un-shaded, giving bright, normal sunlightconditions. Measurements and numerical values represent averages oftypical plant types.

-   Botanical classification: Physocarpus opulifolius ‘SMNPOTWG’.-   Propagation:    -   -   Time to initiate roots.—About 24 days at approximately 25°            C.        -   Root description.—Fine, and freely branching, both fibrous            and fleshy.        -   Time to produce a liner.—About 60 days at 24° C.-   Plant:    -   -   Plant type.—Shrub perennial.        -   Age of plant described.—Approximately 2 years old.        -   Growth habit.—Upright, rounded.        -   Pot size of plant described.—2 gallon pot.        -   Height.—Approximately 28 cm to top of foliage.        -   Plant spread.—Approximately 40 cm.        -   Growth rate.—Moderate.        -   Plant vigor.—Strong.        -   Branching characteristics.—Free, basal branching when            pinched.        -   Length of primary lateral branches.—Approximately 20-30 cm.        -   Diameter of lateral branches.—Approximately 0.3 cm.        -   Quantity of lateral branches.—Minimum average 50.        -   Stem.—Appearance: Rounded, slight pentagonal shape            Aspect/Angle: Some 20° others 90° Strength: Strong Stem            pubescence: None Stem Color: Near RHS Yellow-Green 144B Bark            color: Near RHS Brown 200D.        -   Internode length.—Average range 2 to 3 cm.-   Foliage:    -   -   Leaf.—Arrangement: Alternate, single. Average Length:            Approximately 4.5 cm. Average Width: Approximately 3.4 cm.            Shape of blade: Cordate, Tri-lobed Apex: Acute. Base:            Rounded Attachment: Stalked. Margin: Serrate-dentate.            Texture of top surface: Smooth Texture of bottom surface:            Smooth. Pubescence: None Color: Young foliage upper side:            Near RHS Green 144C Young foliage under side: Near RHS Green            144C Mature foliage upper side: Near RHS Green 143C Mature            foliage under side: Near RHS Green 139C Venation: Type:            Palmate Venation color upper side: Near RHS Green 143C            Venation color under side: Near RHS Green 139C. Petiole:            Average Length: Approximately 1.7 cm. Diameter:            Approximately 0.1 cm Petiole color upper side: Near RHS            Green 143C Petiole color lower side: Near RHS Green 144B.            Petiole Texture upper side; Glabrous, two ridges rim on the            edges of the petiole. Petiole Texture lower side; Glabrous.-   Flower:    -   -   Natural flowering season.—May-June.        -   Inflorescence type and habit.—Terminal and axillary rounded            cyme.        -   Quantity of flowers per inflorescence.—Average range 31 to            40.        -   Inflorescence size.—Width: Approximately 3.5 cm. Height:            Approximately 2.8 cm.        -   Quantity of flowers per lateral stem.—200 to 800.        -   Quantity of flowers per plant.—2000 to 8000.        -   Individual flowers.—Flower form: single whorl of five petals            Flower Aspect: Upright and outward Size: Diameter:            Approximately 0.7 cm Length: Approximately 0.5 cm Depth:            Approximately 0.4 cm Persistence: Persistent.        -   Petal.—Petal arrangement: Whorl Number of petals per flower:            5 Petal appearance: flat, white, rounded Petal Shape:            Obovate. Margin: Entire. Tip shape: Obovate Length: 0.3 cm            Width: 0.2 cm Texture: Upper: Glabrous Lower: Glabrous.        -   Petal color.—When opening: Upper surface: Outer edge near            RHS Red-Purple 63C; rest near RHS White 155D Lower surface:            Outer edge near RHS Red-Purple 63C; rest near RHS White 155D            Fully opened: Upper surface: Near RHS White 155D Lower            surface: Near RHS White 155D Fading: Upper surface: Near RHS            White 155A Lower surface: Near RHS White 155A.        -   Petalloids.—None present.        -   Bud.—Shape: Globose Length: Approximately 0.3 cm Diameter:            Approximately 0.3 cm Color: Near RHS White 155D, maturing to            near RHS Red-Purple 62B.        -   Sepals.—Shape: Triangular Arrangement: Whorl Length:            Approximately 0.2 cm Width: Approximately 0.15 cm Margin:            Entire Base: Connected, Obtuse Tip: Acuminate Texture:            Pubescent Color: Immature: Near RHS Yellow-Green 144B            Mature: Near RHS Yellow-Green 145C.        -   Peduncle.—Length: Average 2.0 cm. Diameter: 0.2 cm Color:            Near RHS Yellow-green 144B Orientation: 60° from stem,            straight. Strength: Good Texture: Glabrous.-   Reproductive organs:    -   -   Stamens.—Number: 20 Filament length: Approximately 0.2 cm            Filament color: Near RHS White 155A.        -   Anthers.—Shape: Globose Length: Less than 0.1 cm Color:            Immature: Near RHS Red-Purple 58D When Fading: Near RHS            Greyed-Orange 177A Pollen: Some Pollen Color: Near RHS White            155A.        -   Pistil.—Number: Average of 4 Length: Approximately 0.3 cm            Style: Length: Approximately 0.3 cm Color: Near RHS White            155B Stigma: Shape: Club-shaped Color: Near RHS Yellow-green            153D Ovary color: Near RHS Yellow-Green 151D.-   Other characteristics:    -   -   Seeds and fruits.—Not observed to date.        -   Garden performance.—Very good.        -   Disease/pest resistance.—Good resistance to Powder Mildew.            Neither resistance nor susceptibility to pests common to            Physocarpus have been observed.        -   Temperature tolerance.—The new variety tolerates            temperatures between −31 to 38 ° C.

What is claimed is:
 1. A new and distinct cultivar of Physocarpus plantnamed ‘SMNPOTWG’ as herein illustrated and described.